The Beyerdynamic MM 1 is a measurement microphone designed specifically for measuring sound reinforcement and PA systems. It is designed to work with spectrum analyzers for measuring frequency response and sound pressure levels of loud speaker systems. The MM 1 is the ideal microphone for the measurements of audio signals in the research, development, for reverberation testing and other applications.

The MM 1 mic's narrow tubular construction ensures that the microphone has negligible influence on the sound field so that an increase in pressure level is avoided due to the linear frequency response.